A biopsychosocial proposal to progress the field of anorexia nervosa

Anorexia nervosa remains vexing to treat with the illness having a decades-long trajectory in most patients, even those in whom intervention has been early. Despite the severe, enduring and often relapsing course, 75% or more ultimately do recover. Mortality rate from the illness, high though it is, has been reduced with better medical salvage and management of the long-term complications but suicide rate increases after 15 years of illness particularly in the context of substance abuse and socioeconomic disadvantage. Neuroprogression has been mooted but thus far has not been satisfactorily distinguished from the effects of continuing brain starvation (Russell et al., 2019).

Anorexia nervosa bears some resemblance to other serious mental illnesses where a substantial number of sufferers remain symptomatic with cognitive and social decline despite what Phillipou et al. (2019) describe rather naively as ‘effective evidence-based treatments’. Genetic studies have shown an overlap between schizophrenia, mood disorders and anorexia nervosa. Autistic social deficits and cognitive rigidity may be premorbid in anorexia nervosa but are exacerbated by weight loss and serve to lock the sufferer into a self-perpetuating vicious cycle. The prospect of eventual full recovery, however, sets anorexia nervosa apart from other serious mental illnesses (Russell et al., 2019).

Of course, effective biological treatment for anorexia nervosa does exist – namely refeeding or nutritional rehabilitation. This can bring about complete resolution of physical, endocrine and psychological symptoms, as documented from the earliest descriptions of the condition. However, it is not always easy to effect (or to complete), often unacceptable to patients and even their families who may see it as persecutory. Maintaining the improved state of nourishment is another challenge, with the patient often unable or unwilling to continue with the behavioural changes. Shifting the patient’s mind-set around this and correcting the system of perverse reward in a lasting way continue to be extraordinarily difficult despite involvement of family and friends as cotherapists and numerous proven psychological treatments. These have been informed by the role of diverse factors such as temperament, traits, emotional skills, trauma and distorted body image in aetiogenesis and perpetuation (Keiser et al., 2016; Russell et al., 2019).

The main source of difficulty psychologically is that patients with anorexia nervosa with few exceptions differ from patients with most other mental or physical illnesses in that they are unwilling to relinquish their symptoms (i.e. emaciation and engagement in nourishment controlling behaviours) as these seem to assuage a pervasively low sense of self-worth and lack of agency. This reluctance underpins the egosyntonicity, dishonesty and treatment sabotage so frustrating to carers and clinicians (Russell et al., 2019). Patients for their part often feel hopeless to change.

Psychotropic medications have been shown to reduce quasi psychotic and obsessive symptoms and to promote weight gain. Anxiety and depression are consequences of prolonged brain starvation (if not premorbid) and may respond to medications targeted to these symptoms even if efficacy is less in the starving brain (Russell et al., 2019). It might be said, however, that food is the miracle drug in anorexia nervosa – if only patients could be persuaded to take it!

A number of potentially reversible neurobiological phenomena have been demonstrated including loss of white and grey matter, changes in brain metabolites, altered connectivity (Phillipou et al., 2019) and reward processes secondary to dysregulated endocannabinoids and oxytocin where potential treatment benefits have been demonstrated (Brockmeyer et al., 2018; Russell et al., 2019). Neuromodulation has shown therapeutic promise (Brockmeyer et al., 2018) while at the other end of the body, work on the microbiome has thus far demonstrated some lack of diversity at low weight with partial restitution after refeeding, raising questions about nutrient extraction and brain effects (Mack et al., 2016).

There was no real epidemic of anorexia nervosa until market deregulation in the early 1970s and the ensuing glut of cheap consumables, mass produced in the third world. This spawned an advertising juggernaut which is still selling an unattainable image targeted to suggestible young people in whom the sense of self is poorly developed. Social media has amplified the problem along with the erosive effect on self-worth. This is in the context of spiritual bankruptcy and decline of the family in a world where leadership is increasingly erratic and threat looms not to mention climate change. Little wonder then that anorexia nervosa has become a new religion.

It is not true to say that progress in uncovering aetiological and maintenance factors in anorexia nervosa has stalled and a biopsychosocial lens has not been employed. However, this has not made the condition any easier to treat. No miracle cure (apart from food) has come to light. Refeeding is undoubtedly an effective biological treatment. Difficult though this might be, it is achievable. We are still too often stymied by the task of securing and maintaining an appropriately fed state in someone whose self-worth depends on denying themselves this basic human right in our apocalyptic times. That is the real challenge.